Stmicroelectronics International N.v.

Rupesh Singh

Ankur Bal

Vivek Tripathi

Sri Ram Gupta

Provided are a method and apparatus for controlling a skew between multiple data lanes. In the method and apparatus, a first data lane control stage controls control outputting first data over a first data lane based on a first data lane clock and a second data lane control stage controls outputting second data over a second data lane based on a second data lane clock. In the method and apparatus, a first device is associated with a system clock and is configured to generate the first and second data for outputting over the first and second data lanes. A clock control stage causes the first and second data lane clocks to be offset from each other by a fixed time duration that is an integer fraction of a cycle duration of the system clock.

Control of skew between multiple data lanes

An integrated circuit includes a serializer configured to receive first test data in n-bit words and to generate a single bit data stream by serializing the test data in accordance with a first clock signal. The integrated circuit includes testing circuitry configured to test the serializer without utilizing a deserializer.

Low overhead loop back test for high speed transmitter

A serial-connection is tested by transmitting a PRBS generated using a kth-order monic-polynomial from transmission-circuitry to reception-circuitry, and determining operation is proper based upon the PRBS received. The PRBS is formed by generating x intermediate-words of the PRBS, x being a result of an integer-divide between a total number of bits in the PRBS and a bit-width of a serializer that transmits the PRBS, generating a leading-word of the PRBS as having first y-bits of the PRBS as its LSBs, y being based upon a modulo-divide between the total number of bits in the PRBS and x, and generating a trailing-word of the PRBS as having last z-bits of the PRBS as its MSBs, z being based upon a difference between a result of the modulo-divide and y. The PRBS is transmitted sequentially as the leading-word of the PRBS, the intermediate-words of the PRBS, and the trailing-word of the PRBS.

Method and architecture for serial link characterization by arbitrary size pattern generator

Individual bits of a K bit unary data word, wherein K is greater than one, are applied to K polyphase finite impulse response filter circuits. Each polyphase finite impulse response filter circuit receives a different bit and operates with a single bit precision to generate from each received bit a filtered output data word. A gain adjustment is applied by a gain stage circuit to each filtered output data word to generate a corresponding gain adjusted output data word. The gain adjusted output data words from the gain stage circuits are summed to generate an output data word. The unary data word may be output from a source such as a data encoder or a quantizer.

High throughput digital filter architecture for processing unary coded data

A first multiplier multiplies a first input with a first coefficient and a first adder sums an output of the first multiplier and a second input to generate a first output. A second multiplier multiplies a third input with a second coefficient, a third multiplier multiplies a fourth input with a third coefficient, and a second adder sums outputs of the second and third multipliers to generate a second output. The second and third inputs are derived from the first output and the first and fourth inputs are derived from the second output. The first and second outputs generate digital values for first and second digital sinusoids, respectively.

High throughput parallel architecture for recursive sinusoid synthesizer

An integrated circuit includes a first subsystem including a first clock generator configured to generate a first clock signal. The integrated circuit also includes a second subsystem including a second clock generator configured to generate a second clock signal. The first subsystem include a clock edge selector configured to determine a phase difference between the first clock signal and the second clock signal and to select, based on the phase difference, either a rising edge or a falling edge of the second clock signal to control output of data from the first subsystem to the second subsystem.

Data bridge for interfacing source synchronous datapaths with unknown clock phases

A latch circuit sequentially latches a first data weighted averaging (DWA) data word and then a second DWA data word. A first detector circuit identifies a first bit location in the first DWA data that is associated with an ending of a first string of logic 1 bits in the first DWA data word. A second detector circuit identifies a second bit location in the second DWA data word associated with an ending of a second string of logic 1 bits in the second DWA data word. A DWA-to-binary conversion circuit converts the second DWA data word to a binary word by using the first bit location and second bit location to identify a number of logic 1 bits present in said second DWA data word. A binary value for that binary word that is equal to the identified number is output.

High speed data weighted averaging (DWA) to binary converter circuit

An integrated circuit includes a successive approximation register (SAR) analog-to-digital converter (ADC). The ADC includes a bit step selector. During testing of the ADC, the bit step selector selects a number of bits to be tested for a next analog test voltage based on digital values that are within an integer delta value of most recent digital value for a most recent analog test voltage.

Method and device for testing successive approximation register analog-to-digital converters

A quantizer generates a thermometer coded signal from an analog voltage signal. Data weighted averaging (DWA) of the thermometer coded signal is accomplished by controlling the operation of a crossbar switch controlled by a switch control signal to generate an output DWA signal. The output DWA signal is latched to generate a latched output DWA signal which is processed along with bits of the thermometer coded input signal in feedback loop to generate the switch control signal. The latching of the output DWA signal is performed in an input register of a digital-to-analog converter which operates to convert the latched output DWA signal to a feedback analog voltage from which the analog voltage signal is generated. The switch control signal specifies a bit location for a beginning logic transition of the output DWA signal cycle based on detection of an ending logic transition of the latched DWA signal.

First order memory-less dynamic element matching technique

A first sampling circuit takes phase offset first samples of a received serial data stream in response to a first edge of a sampling clock and a first comparator circuit determines whether the plurality of phase offset first samples have a same logic state. A second sampling circuit takes phase offset second samples of the received serial data stream in response to a second edge of the sampling clock, opposite the first edge, and a second comparator circuit determines whether the phase offset second samples have a same logic state. One of the first samples or one of the second samples is then selected in response to the determinations made by the first and second comparator circuits. A serial to parallel converter circuit generates an output word including the selected one of the first and second samples.

Clock and data recovery circuit

A recursive digital sinusoid generator generates recursive values used in the production of a digital sinusoid output. The recursive values are generated at a first frequency. A sinusoid value generator generates replacement values at a second frequency, wherein the second frequency is less than the first frequency. The generated recursive values are periodically replaced with the generated replacement values without interrupting production of the digital sinusoid output at the first frequency. This periodic replacement effectively corrects for a finite precision error which accumulates in the recursive values over time.

Digital sinusoid generator

A sigma-delta modulator includes an N-bit quantization circuit that generates a stream of N-bit code words and a feedback signal path with an N-bit DAC circuit, having a non-ideal operation due to mismatch error, that converts the stream of N-bit code words to generate a feedback signal. A digital DAC copy circuit provides a digital replication of the N-bit DAC circuit. The digital replication accounts for the non-ideal operation of the N-bit DAC circuitdue to mismatch error, and converts the stream of N-bit code words to generate a stream of P-bit code words, where P&#x3e;N, that are functionally equivalent to the feedback signal output from the N-bit DAC circuit.

Sigma-delta analog-to-digital converter circuit with correction for mismatch error introduced by the feedback digital-to-analog converter

A continuous time Delta-Sigma (CT-&#x394;&#x3a3;) modulator has an input node configured to receive an input signal and an output node configured to output a digital output signal. The CT-&#x394;&#x3a3; modulator includes a feedback loop with a summation circuit configured to sum the digital output signal with a jitter perturbed test signal to generate a signal supplied to an input of a digital to analog converter circuit. A single tone signal is injected with a jitter error of a clock signal to generate the jitter perturbed test signal. A processing circuit processes the digital output signal to detect a signal to noise ratio of the CT-&#x394;&#x3a3; modulator. The detected signal to noise ratio is indicative of presence of jitter in the clock signal.

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Ghaziabad, India

Rupesh Singh